After doing tens of thousands I agree that the proper bit and an impact screwdriver is the best and fastest way to remove the boards from the desktop hd's....I do use the prying method for the laptop hd's

( 1 )
I've always thought they get clamped into a sliding jig and theres a spinning Circular disc the size of a record ( 12 inch dia ) with a very sharp outer edge. Its at a slight angle of say less than 5°.
Its touched to the edge of the board, and then the board is slid under the spinning disc.
That slices all of the components off at board level.

They get dropped onto a conveyor which spits the nonmagnetic pieces out over its end, into mid air, and air seperations used to blast them off in diferent directions into drums for metal recovery.

While magnetic ones get stuck to the magnetic roller & pass over & under the end of the conveyor, past the magnetic roller until they fall into their own drum.

OR ( 2 }

They get put into a large mesh container & dumped into a vat of hot Hydrochloric acid where the solders dissolved & the components fall into a recovery pan.
Components are then removed, washed, dried, sorted & processed.
The board itself is mulched into pulp & the Copper is dissolved out & recovered ( along with Gold, Brass, Tin & Copper ) They do this to the boards above too.

OR. { 3 )

Its a Copper mine setup.
The mined Copper granules are put into a melting pot & melted. Then the boards are chucked into the molten Copper, everything melts but the Steel which is removed somehow. The boards act as a flux or to cover the molten metal & are skimmed off before pouring.
The Copper mix is poured out as bars or such. Then rolled or granulated or something.
Then its put into a electroplating bath & the Coppers dissolved & plated onto sheet electrodes while thecother metals end up in the sludge & are recovered thru many, mostly electroplating, processes.

Since all of this is done to mined Copper anyway, adding the boards simply raises the 'other metals' content & thats how they get the escrap $$ back.

In this case, the condition of the boards won't matter much, ripped, broken or damaged would still be ok & the quality could vary from above 'Power supply' to ' High grade telecom',
The prices paid for the scrap would be lower because theres less work needed for sorting boards out by the sellers & the process is more basic, it would take longer to do & the extra transport costs to remote Copper mines & refinerys.

While in process 1 & 2.
In 1,. Any boards would be processed dry & even power supplys because Aluminium capactors & Ferrite coils, chokes & transformers get seperated out immediately & every type of component gets its own bin for bulk taylored processing.

While in ( 2 ) each sort of board would be saved up & processed in bulk, even indicidual board sorts would be regraded before processing.
Say, Memory sticks would be graded into size of the board, & year of manufacture & memory capacity.
The actual recovery of Gold & such would be already known before the process is started. That way when they do the next processes they know how much they will get & when to stop processing. ( Electroplating metals out )

Hard drive boards have the best recovery from what I have read, certain years of manufacture used the yellow block Tanti capactors. Thats just one way they would seperate the boards.
But i think they would seperate them into individual models of boards.

I figured if its process ( 1 ), the skimming of the components off the boards with a knife, that the boards could not be damaged in almost any way.

Boards are shredded, sometimes blended with other materials, to get the copper content higher.
The shredded boards are smelted and copper cathodes are poured. The copper acts as a collector of all the precious metals. Iron, aluminum, etc go in the slag.
The copper cathodes are placed in an electrolytic cell, and current is applied. The copper will dissolve and get deposited on the cathode as pure copper (99.99% or so).
All the precious metals and other impurities fall to the bottom of the tank, called anode slimes.
The anode slimes are further processed to separate the various precious metals and purify them.

This would be basically the same process for all ewaste on a large scale. Companies like Umicore, Boliden, Metalor, etc use some variation of this process.
Depopulating boards and separating components is usually only done by small scale or home refiners.